Heater



July 20, 1948.

B. DE LORENZO HEATER Filed Ap'ril 17, 194:5

2 Sheets-Sheet 1 2 Sheets-Sheet 2 July 20, 1948. B. DE LORENZO HEATER Filed April 17, 1945 Patented July 20, 1948 Bartholomeo De Lorenzo, Elyria, Ohio,

to Foster Wheeler Corporation, `New assigner York,

N. Y., a corporation of New York Application April 17, 1943, serial No. 483,535

This invention relates to heaters, and more particularly pertains to tubular heaters for heating fluids such as hydrocarbon oils and the like,

although it is applicable to the rheating of fluids Y generally.

The invention provides a tubular fluid heater of vsimple and economical design and construction in which substantially uniform heating of all the tubes in the furnace of the heater is effected.

The invention will be understood from the following description whenvconsidered in connection'withvthe accompanying drawings, forming apart thereof, and in'which:

Fig.' 1 is a transverse vertical sectional view onthe line I--I of Fig. 2 of a heater embodying the invention;

Fig.l 2 isa longitudinal vertical sectional view takenon line 2-2 of Fig. 1, and

' Figs. 3, 4 and 5 vare vertical, transverse, sectional views taken on lines'3--3, 4--4 and 5-5 respectively, vof Fig. 2. 3* Like characters of vreference refer to the same parts in the several views.

v-Referring to the drawings, the heater has a setting including vertical side walls I0 and II, sloping side walls I2 andl3, end walls I4 and I5, a roof I6 yand a bottom II. Suitable framework designated generally I8, supports the walls and roof of the setting. The walls of lthe setting enclose a furnace I 9 whichis fired; as shown, by fuel burners 20 and 2l locatedv in the 'end walls I4 and I5 respectively, in the lower central portion thereof. The side walls andr roof Vare lined with fluid conducting tubular members which are heated principally by radiation from the products'of combustion produced by the burners 20 and 2I Vertical side walls I0 andv II have horizontally extending tubular members 22 and 23 respectively,` supported adjacent thereto by the tube supports 24.' The VslopingV sidewalls I2 and I3 have similar tubular members 25 and`26 respectively, hung adjacent thereto by `supports'21', and tubes l28 vare supported below the roof lby hangers 29. The tubes adjacent the side walls and roof are connected bysuitable return bend portions which may be disposed within the heater or outside of the end walls thereof.

The heater has a convection tube bank 30 above the bottom I'I 'which is located approximately midway between the side wall I0 and I-I and which extends the full lengthvof the furnace. As shown, the convection bank comprises three superposed rows of tubes with the tubes of each 12 Claims. (Cl..122-356) rowf arranged in staggered relationship with respect to the tubes of the adjacent row. A baille 3l is supported above the tube bank 33 by tile 32 which rest upon theupper rows of the tubes of the bank 30. Walls 33 and 34 extend'ffrom the bottom IT to the baffle 3| adjacent the tube bank 30 and enclose the sides of the convection bank to thereby forma passage`31 for the fur nacegases. The ends of the baille 3| and-the walls 33 and 34 are disposed in'spaced relationship tothe end walls I4 and-.I5,.toprovide furnace gas openings or passages 35 and 36 through which. the gases flow from the furnace into the4 convection heating' passage 31 in which the conevection tube bank 30 is disposed. From the passage'y l31, the-1gasesflow into a central, downwardly 'extending gas flue 39, which discharges into a flue 40 which connects with a stack, not shown."l f In the form of the invention illustrated, the tubes 30of the convection bank have extended surface'r elements' 4I on the portions thereof which extend between the ends of the baille 3l. and the gas flue 39. The extended surface elements 4I comprise longitudinally extending U-'shapedor channel members welded tothe aforesaid portions of the tubes, although other types'or shapes of extended surface elements mayv be employed, if desired. The portions of the tubes 3U which are beneath the baille 3| .and adjacentthe openings 35 and 36 are provided with-a suitable `or desired number of extended surface elements, while the other portions of the tubes 30 beneath thebafile 3| and which extend to the gas outlet 39, have a greater number of extended' surface elements, approximately twice as many, as shown inV Figs. 2, 3 and 4. With this arrangement, the heat absorbed by the convection tubes 30 is substantially equalized throughout their lengths. v

The tubes 30 are vsupported at their ends by tube sheets 42 and 43, Fig. 2, and they are supported intermediate their ends by novel means. In the' form shown, such novel supporting means comprises a plurality of relatively narrow metallic straps 44 which extend transversely about the extended surface elements 4I of the tubes'- of the upper and lower rows of tubes 30 and engage-a substantial portion of the extended surface elements of the tubes of the intermediate row, as shown in Fig. 5. The straps 44 are made into loops 0f the desired lengths by welding their'ends together, and the intermediate portions'of the*y loops are brought into contact and are welded together as indicated at 45. The

3 loops are placed in lateral alignment and are welded together at their upper and lower portions as indicated at 4-6 and 41. The lower end of each strop is attached to a bar 48 by welds 49. These tube supports are fabricated and are placed in position, and the tubes 3l] are passed through them and through the tube holes in the tube sheets. The tubes of the upper and lower rows extend through the loops while the tubes of the middle row extend between adjacent loops. rlhe bars 48 rest upon the bottom I1 of the furnace. With this arrangement, the tubes are supported adequately intermediate their ends without being secured to the supporting straps, and one or more tubes may be removed and replaced l refractory, the overall weight of the heater on at will Without materially affecting the support of the adjacent tubes, as will be apparent from an inspection of Fig. 5.

In the form shown, the fluid to be heated flows through the heater in two separate streams. Fluid enters the convection bank 3B through an inlet. 5t, Fig. l., and after iiowing through part of the tubes of bank the fluid flows through cross-over connection 5| to the wall tubes 22,

and through these tubes in series, and through sloping wall tubes and roof tubes 28 to outlet 52.. Fluid ows similarly through the other side of the heater, entering at inlet 50, owing through the other tubes of convection bank 30, through cross-over connection 53, through wall tubes 23, sloping wall tubes 26, roof tubes 28 and through outlet 52. Other fluid flow arrangements may be employed, if desired, and separate inlets and outlet connections may be utilized for each path of now. y

In operation, the hot products of combustion produced by the burners 20 and 2l stream from the burners and rise toward the roof. `The gases are cooled by radiation of heat to the fluid conducting tubes in the furnace, and fall of their own `weight and under the influence of the draft provided at the bottom of each end of the furnace, toward the gas openings and 36. VThe gases thus form a symmetrical pattern with relation to the radiant heat absorbing tubes in the furnace and thereby effect substantially nniform heating of all the tubes in the furnace. By controlling the burners, the quantityof heating gases produced on either side of the furnace may be controlled and varied, to control the amount of heatsupplied to the tubes on either side of the furnace and to vary the temperature to which the fluid flowing through either flow path is heated. The gases flowing from the furnace flow longitudinally over the tubes Iof the convection lbank 3 from Aboth ends of the furnace to the flue 39 and through the flue 40 to the stack. Due to the extended surface elements and their location and number, the tubes 30 are heated approximately evenly throughout their lengths.

Fluid heaters embodying the invention possess numerous advantages, among which the following may be mentioned. Inasmuch as little wall surface is exposed to direct radiant heat, the setting dimensions, particularly the height of the heater, are minimized with consequent economy in rst cost. The sloping side walls eliminate corners which generally are cold spots vin the furnace, and tend to provide a more even heat absorption throughout the radiant section of the heater. The sloping walls also make it possible to utilize a roof cover which is simple and inexpensive. No roof trusses are necessary and very little steel is required for the roof cover, although the top and sloping sides of the heater yits foundation is low.

No bridge walls are required inasmuch as the The floor construction is inexpensive be- .cause the tile composing the baille is supported directly on the tubes of the convection bank.

1v Although the tile composing the baffle shields the upper row of convection bank tubes to some eX- tent, the heat passingthrough this baille by conduction, compensates considerably for the shielding of the top row of tubes of the convection bank. Due to the use of the extended surface elements on the tubes of the convection bank, the number of tubes in the bank can be reduced with consequent reduction in the number of return bends or headers kand joints. The convection bank tube sheet area is reduced because the outlet gas passage 31 is directly adjacent the first rows of convection tubes. In conventional heaters, the convection tube bank usually is elevated a considerable distance above the floor, thus requiring substantially more tube sheet area than is necessary with heaters embodying the invention. Due to the light weight and simple construction of the framework of the heater, the time required for erection is shortened. The arrangement of thev radiant heating surface in the furnace approximates a half circle about the burners, so that all of the radiant tubes are approximately equi-distant from the burners. The cross-over connections which usually constitute an expensive item, are short and are of simple construction due to the fact that the bottom radiant tubes are close to the top of the convection tubes to which they are connected. The dimensions and arrangement of the setting are such that the expansion of the brick work is small and can readily be taken care of, so that expansion throughout the heater is not a difficult problem.

Although the invention is disclosed as embodied in a heater fired from both ends, it will be understood that heaters embodying the invention may be fired from one end only, if desired. Moreover, the convection tube bank may be disposed adjacent one or both of the side walls instead of approximately midway between these walls, as illustrated.

Changes may be made in the form, location and relative arrangement of the several parts of the heater disclosed without departing from the principles of the invention. Accordingly, the invention is not to be limited excepting by the scope of the appended claims.

What is claimed is:

. 1. Apparatus for heating fluids comprising walls forming a furnace, fuel burner means disposed vin opposite walls for firing the furnace, fluid conducting tubular members adjacent otherv oppositely disposed Walls adjoining said opposite walls. a bank of tubular members at the bottom of the furnace extending toward said op: posite walls, a wall at each side of said banks 0f for gas,l said passage having terminal portions .spaced fromy oppositewalls `to provide gas openings into said passage, the said bank of tubular members projecting from each end of saidgas passage, longitudinally extending ns on those portions only of the tubular members--of said bankwhich lie below said baille, and means forming a iiue to receive the gasesiiowing from said bank. f

2. Apparatus for heating `iiuids comprising Walls-forming a furnace,A fuel burner means disposed in op-posite walls for firing the furnace, fluid conducting tubular members adjacent other oppositely disposed walls adjoining said opposite Wa1ls,fa bank of tubularfmembers at the bottom of ,the furnace extending toward said opposite walls, a Wall at each side of said bank of tubular members, a -baiiie -above said bank and said walls, said baille and walls forming a passage for gas, said passage having terminal portions spaced .from-,opposite Walls to provide gas openings into said passage, the said ybank of tubular members projecting from each 'end of said gas passage,

`longitudinally extending fins on those portions onlyof the tubular members of said bank which lie below said baffle, and means forming a flue to receive the gases flowing from said bank, there vbeing* a greater numberfofr fuis on those portions ofthe ltubular members o-f said bank which are adjacent said ue than on those portions which `are adjacent said gas openings to substantially equalize the heat input to the tubular members of -said bank.

YA3. Apparatus for heating fluids comprising Walls forming a furnace, each side wall having a -vertically extending portion and a vertically and inwardly inclined portion above the vertically extending portion and connecting with the roof of the furnace, fluid conducting tubular members adjacent the side walls of the furnace, fuel burner ,those portions only of the tubular members of said bank which lie below said baflie, and means forming -a flue to receive the gases owing lfrom said bank, there beinga greater numberof fins o n those portions of the tubular members of said bank which are adjacent said ue than on those portions which are adjacent said gas openings to substantially equalize the heat input to the tubular members of said bank.

4. Apparatus for heating uids comprising walls forming a furnace, fuel burner means lpositioned in at least one wall of oppositely disposed walls for firing the furnace, iiuid conducting tubular members adjacent other oppositely disposed walls adjoining said first-mentioned oppositely disposed walls, gas passage forming means forming a gas passage at the bottom of the furnace extending toward said first-mentionedv oppositely disposed Walls, a bank fof tubular members in said passage and extending toward said first-mentioned oppositely disposed Walls, said passage fonming means including a baille above said bank of tubular members having terminal portions; spaced from said first mentindop Ypositeli'/ :disposed walls to provide` gas openings fron'rthe furnace, -andfmeans `for-ming a flue to receive the gases flowing from said bank.

5. Apparatus "for heating iiuids comprising walls forming a furnace, fuel burner means dis.- posed in .opposite Walls for firing the furnace,

-iiuid conducting tubular members adjacent `other oppositely disposed Walls adjoining said opposite Walls, gas passage forming means forming a gas passage at the bottom of the furnace extending toward said opposite Walls, a bank lof tubular members in said passage and extending toward -sai'd first-mentioned oppositely disposed walls,

said passage forming means including a baffle above'said bank of tubular members having terminal portions spaced from said opposite walls to provide gas openings from the furnace, and means forming a flue to receivethe gases flowingfrom said bank.

f6. Apparatus for heating iiuids comprising walls forming a furnace, fuel burner means positioned in at least one wall of oppositely disposed walls for firing thefurnace, iiuid conducting tubularv members adjacent other oppositely disposed Walls adjoining said first-mentioned oppositely disposed Walls, gas passage forming means forming a gas passage at the bottom of the furnace extendingtoward said first-mentioned oppositely disposed wa1ls,a bank of tubular members in said passage and extending toward said first-mentioned oppositely disposed walls, said passage forming means including a baffle above said bank of tubular members havingterminal portions spaced from said first-mentioned oppositely disposedwalls to provide gas openings from the furnace, longitudinally extendingns on the portion of the tubular members ofsaid Ybank which liesbelow the baille, and means fomiing a flue to receive the gases flowing from said bank. I

' 7'. Apparatus for heating fluids comprising walls forming a furnace, fuel burner means positioned in at least one wall of oppositely disposed walls for firing the furnace, fluid conducting tubular members adjacent other oppositely disposed walls adjoining said nrstmentioned foppositely 'disposed walls, gas passage forming means forming a gas passage at the bottom of the furnace extending toward said first-mentioned oppositely disposed walls, a bank of tubular members in said passage and extending toward said first-'mentioned oppositely disposed walls, said passage forming means including a baffle above said bankof tubular members having terminal portions spaced from said first-mentioned oppositely disposed Walls to provide gas openings from the furnace, longitudinally extending fins on the portion of the tubular members of said bank which lies below the baffle, and means forming a flue in communication with said passage intermedi-ate the opposite ends thereof to receive the gases flowing from said bank, there being a greater number of fins on those portions of the tubular members of said bank which are adjacent .said flue than on those portions which are adjacent said gas openings to substantially equalize the heat input to the tubular members of said bank.

8. Apparatus for heating fluids comprising walls forming a furnace, fuel burner means positioned in at leas-t one Wall of oppositely disposed Walls for firing the furnace, fluid conducting tubular members adjacent other oppositely disposed yWalls adjoining said first-mentioned oppositely kenr-5,316

disposed walls, means forming a 'gas' passage at the bottom of the furnace extending toward said first-mentioned opposi'tely disposed walls, a bank of tubular members in said passage and extending toward `the nist-mentioned oppositely disposed walls, said passage having a gas opening adjacent each of said first-mentioned oppositely disposed walls, and means forming a flue to receive gases owing from said passage after passing in heat exchange relationship with the bank of tubes therein.

9. Apparatus for heating fluids comprising walls forming a furnace, fuel burner means positioned in at least one wall of oppositely disposed walls for firing the furnace, fluid conducting tubular members adjacent other oppositely disposed walls .adjoining said first-mentionedoppositely disposed walls, means forming a gas p-assage at the bottom of the furnace intermediate said other oppositely disposed walls of the furnace, said gas -passage extending toward said first mentioned oppositely disposed walls, a bank of tubular members in said passage and extending toward the first-mentioned oppositely disposed walls, said passage having a gas opening adjacent each of said first-mentioned oppositely disposed Walls, and means forming a flue to receive gases flowing from said passage after passing in heat exchange relationship with the bank c-f tubes therein.

10. Apparatus for heating fi-u-ids comprising walls forming a furnace, each side wall having a vertically extending portion and -a vertically and inwardly inclined portion above the vertically extendingk portion and connecting with the roof lof the furnace, fluid conducting tubular members adjacent the side walls of the furnace, fuel burner means in at least one Iof the end walls of the furnace for firing the furnace, means forming a g-as passage at the bottom of the furnace intermediate the side walls and extending toward said end walls, a bank of tubular members in said passage and extending toward the ends walls, said passage having a gas opening adjacent each of said end walls, and means forming a flue to receive gases flowing from said passage after passing in heat exchange relationship with the bank of tubes therein.

11. App-aratus for heating fluids comprising walls forming a furnace, fuel burner means positioned in at least one wall of oppositely disposed walls for ring the furnace, fluid conducting tubular members 'adjacent other oppositely disposed walis adjoining said first-mentioned oppositely disposed Walls, means forming a gas passage at the bottom of the furnace intermediate two oppositely disposed walls and extending toward two other oppositely disposed walls, a bank of tubular members in said passage and extend- `ing toward said two other oppositely disposed walls, said passage having a gas opening adjacent each of said two other oppositely disposed walls, and means forming a flue in communication with said passage and positioned in longitudinally space relationship to and substantial equi-distant from said openings to receive gases owing from said passage after passing in heat exchange relationship with the bank of tubes therein.

12. Apparatus for heating fluids comprising walls forming a furnace, each side Wall having a vertically extending portion and an inwardly inclined portion above the vertically extending portion and connecting with the roof of the furnace, fluid conducting tubular members adjacent the side walls and roof of the furnace, fuel burner lmeans disposed in the opposite end walls of the furnace for ring said furnace, means forming a gas passage at the bottom of the furnace intermediate the side walls and extending toward said end Walls, a bank of tubular members in said passage and extending toward the end walls, said passage forming means including a baffle above said bank of 'tubular members having terminal portions spaced from said end walls to provide gas openings from the furnace in communication with said passage, longitudinally extending fins on the portion of the tubular members of said bank which lies below the baffle, and means forming a flue in communication with said passage and positioned in longitudinally spaced relationship to and substantially equi-distant from f said gas openings to receive gases flowing from said passage after passing in heat exchange relationship with the bank of tubes therein, there being a greater number -of ns on those portions of the tubular members of said bank which are adjacent said flue than on those portions which are adjacent said openings to substantially equalize the heat input to the tubular members of said bank.

BARTI-IOLOMEO DE' LORENZO.

REFERENCES CITED 'lhev following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,315,225 lHughes Sept. 9, 1919 1,748,140 Muhleisen Feb. 25, 1930 2,151,386 De Florez Mar. 21, 1939 '2,275,412 Becker Mar. 10, 1942 2,276,529 Throckmorton et al. Mar. 17, 1942 2,296,390 Marchant Sept. 22, 1942 Certificate of Correction Patent No. 2,445,316. July 20, 1948. BARTHOLOMEO DE LORENZO Itis hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Col'kumn 3, Line 4, for strop read strap; line 46, for uniform read uniform; column 7, Ime 42, for ends read end; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case 1n the Patent Office.

Signed and sealed this 23rd day of November, A. D. 1948.

THOMAS F. MURPHY,

Assiste/nt Uommesz'oner of Patents. 

